This invention relates to a device for measuring pressure, and in particular to a device for measuring the maximum pressure in a cylinder of an internal combustion engine.
The maximum pressure in a cylinder of an internal combustion engine is typically measured by somewhat complicated mechanical or electromechanical devices. Typical of such devices are those disclosed by U.S. Pat. Nos. 2,202,900, issued to C. S. Draper on June 4, 1940; 2,355,088, issued to S. D. Lavoie on Aug. 8, 1944; 3,216,244, issued to G. W. Borchers on Nov. 5, 1965; 3,633,410, issued to A. A. Isaev on Jan. 11, 1972; 3,943,759, issued to T. Kato et al on March 16, 1976; and 3,983,748, issued to A. A. Isaev on Oct. 5, 1976. Some of the devices, for example, the Draper and Lavoie apparatus, rely on the movement of a rigid diaphragm which is translated into an electromagnetic signal indicative of the rate of change of pressure within a cylinder. Others, including the Borchers device, use spring or valve movement as a means of measuring pressure.
In any event, it is readily apparent from a review of the prior art that a need exists for a simple, accurate device for measuring the maximum pressure in a cylinder of an internal combustion engine.
The object of the present invention is to attempt to meet such need by providing a relatively simple device for accurately measuring the maximum pressure in a cylinder of an internal combustion engine.